1. Field of the Invention
The invention relates to an electronic appliance unit that includes a case provided with an opening that permits access to the inside thereof, and a terminal block that faces the opening provided within the case.
2. Description of Related Art
Generally, electronic components, such as control circuit boards, of electronic appliance units mounted in vehicles and the like, such as inverters and the like, are housed within a case. In some electronic appliance units, an opening that permits access to a terminal block housed within the case is formed in the case, that is, a so-called service hole.
For example, Japanese Patent Application Publication No. 2003-127802 (JP-A-2003-127802) describes a dust-proof and water-proof case for a vehicle in which the access opening is provided with a cover. The dust-proof and water-proof case is provided with a subsidiary cover that covers the access opening in order to prevent entrance of dust through the access opening and that is removed when an attachment component part is to be accessed. With the described case, the entry of foreign objects into the case of an electronic appliance unit may be prevented to a certain degree.
However, although the entrance of foreign objects can be prevented when the access opening is covered with the subsidiary cover, as described in JP-A-2003-127802, the entrance of foreign objects cannot be prevented when the subsidiary cover is removed from the access opening. In some cases, foreign electroconductive objects may enter the inside of the case and come in contact with electronic components provided within the case, such as a control circuit board or the like, and causes a functional fault due to short-circuit.